Equine Veterinarian Dies of Hendra Virus

One of the two equine hospital staff workers hospitalized with Hendra virus in Australia has died. Veterinarian Ben Cunneen, died Aug. 20. He had contracted Hendra virus from a horse hospitalized at the Redlands Veterinary Clinic on the outskirts of the city of Brisbane in the state of Queensland.

A nurse and another veterinarian have also been hospitalized. The nurse and Cunneen were confirmed positive for the virus in mid-July. Both staff members had cared for infected horses at the clinic prior to the diagnosis of Hendra, a known fatal zoonotic virus. Four horses died in this outbreak last month.

According to a report in the Brisbane Times <http://www.brisbanetimes.com.au/news/queensland/hendra-vet-pricked-with-needle/2008/08/19/1218911700928.html>, a Department of Primary Industries veterinarian was also hospitalized after pricking herself with a needle that she had used to euthanize a horse Aug. 15 that had recovered from Hendra. Biosecurity Queensland officials had deemed the horse, although apparently healthy at the time of his euthanasia, to be an unacceptable disease threat. This veterinarian was hospitalized as a precautionary measure.

"This is one of the most deadly viruses known to man," explained Biosecurity Queensland Chief Veterinary Officer Dr. Ron Glanville, in a ProMED-mail post (a program of the International Society for Infectious Diseases) circulated Aug. 21. "It has a mortality rate in horses of over 70%. Not counting the current people in hospital, 50% of previous human cases have died. It is a high-level containment category virus that is only studied in laboratories under the strictest of biocontainment protocols. Hence, it is not something to play around with."

The virus has only been reported in Australia. Fruit bats indigenous to the continent appear to be its natural host. Typical equine clinical signs of Hendra include respiratory distress, frothy nasal discharge, elevated heart rate, and increased body temperature. Some horses display neurologic signs, such as head-pressing or twitching, while others might appear to be colicky.

However, Glanville noted that the Redlands cases were unusual, in that the affected horses displayed neurologic signs as their main clinical presentation. These signs included ataxia, head tilt, and facial nerve paralysis, in addition to increased temperatures and purple mucous membranes.